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1.
Nutrients ; 16(9)2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38732499

RESUMEN

Individuals exhibiting high scores on the fatness subscale of the negative-physical-self scale (NPSS-F) are characterized by heightened preoccupation with body fat accompanied by negative body image perceptions, often leading to excessive dieting behaviors. This demographic constitutes a considerable segment of the populace in China, even among those who are not obese. Nonetheless, scant empirical inquiries have delved into the behavioral and neurophysiological profiles of individuals possessing a healthy body mass index (BMI) alongside elevated NPSS-F scores. This study employed an experimental paradigm integrating go/no-go and one-back tasks to assess inhibitory control and working memory capacities concerning food-related stimuli across three adult cohorts: those with normal weight and low NPSS-F scores, those with normal weight and high NPSS-F scores, and individuals classified as obese. Experimental stimuli comprised high- and low-caloric-food pictures with concurrent electroencephalogram (EEG) and photoplethysmogram (PPG) recordings. Individuals characterized by high NPSS-F scores and normal weight exhibited distinctive electrophysiological responses compared to the other two cohorts, evident in event-related potential (ERP) components, theta and alpha band oscillations, and heart rate variability (HRV) patterns. In essence, the findings underscore alterations in electrophysiological reactivity among individuals possessing high NPSS-F scores and a healthy BMI in the context of food-related stimuli, underscoring the necessity for increased attention to this demographic alongside individuals affected by obesity.


Asunto(s)
Índice de Masa Corporal , Obesidad , Humanos , Masculino , Femenino , Obesidad/fisiopatología , Obesidad/psicología , Adulto , Adulto Joven , Electroencefalografía , Potenciales Evocados , Memoria a Corto Plazo/fisiología , Frecuencia Cardíaca/fisiología , Inhibición Psicológica , China , Imagen Corporal/psicología
2.
Anal Chim Acta ; 1299: 342417, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38499414

RESUMEN

BACKGROUND: Nitrite has been involved in many food processing techniques and its excessive consumption is closely related to the development of different diseases. Therefore, highly sensitive detection of nitrite is significant to ensure food safety. RESULT: This study presents a simple and novel strategy for the highly sensitive detection of nitrite in food using paper-based analytical devices (PADs). In this proposed strategy, the nitrite present in the sample undergoes efficient diazotization when initially mixed with sulfanilamide solution before reacting with N-(1-naphthyl) ethylenediamine dihydrochloride (NED) coated on the detection region of the PAD, leading to the maximum production of colored azo compounds. Specifically, within the concentration range of 0.1-20 mg/L, the LOD and LOQ for the nitrite assay using the premixing strategy are determined as 0.053 mg/L and 0.18 mg/L, respectively which significantly surpass the corresponding values of 0.18 mg/L (LOD) and 0.61 mg/L (LOQ) achieved with the regular Griess reagent analysis. SIGNIFICANCE: The study highlights the critical importance of the premixing strategy in nitrite detection. Under optimized conditions, the strategy demonstrates an excellent limit of detection (LOD) and limit of quantification (LOQ) for nitrite detection in eight different meat samples. In addition to its high precision, the strategy is applicable in the field of nitrite analysis. This strategy could facilitate rapid and cost-effective nitrite analysis in real food samples, ensuring food safety and quality analysis.


Asunto(s)
Compuestos Azo , Nitritos , Nitritos/análisis , Límite de Detección , Sulfanilamida
3.
Carbohydr Polym ; 321: 121290, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37739526

RESUMEN

Utilizing spent coffee grounds (SCG) to produce high value-added materials is attractive and meaningful. In this work, a multi-functional biomass film is prepared from SCG and dissolving pulp through a dissolution and regeneration process. Importantly, dissolving pulp as a reinforcing additive can significantly enhance the mechanical strength of the regenerated SCG film. The prepared composite films with SCG contents ranging from 33.33 wt% to 81.82 wt% demonstrate excellent optical and mechanical properties. The composite film with 66.67 wt% SCG exhibits outstanding UV blocking capability (99.43 % for UVB and 96.59 % for UVA) and high haze (69.22%); meanwhile, the composite film with 33.33 wt% SCG performs better mechanical strength (58.69 MPa tensile strength and 3.13 GPa Young's modulus) and superior biodegradability (fully degraded within 26 days by being buried in soil) than commercial plastic. This work generally introduces a facile and practical approach to converting waste SCG into promising materials in various fields.

4.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 41(3): 260-268, 2023 Jun 01.
Artículo en Inglés, Chino | MEDLINE | ID: mdl-37277791

RESUMEN

OBJECTIVES: This work aimed to investigate the molecular mechanism of cyclic tensile stress (CTS) stimulating autophagy in human periodontal ligament cells (hPDLCs). METHODS: hPDLCs were isolated and cultured from normal periodontal tissues. hPDLCs were loaded with tensile stress by force four-point bending extender to simulate the autophagy of hPDLCs induced by orthodontic force du-ring orthodontic tooth movement. XMU-MP-1 was used to inhibit the Hippo signaling pathway to explore the role of the Hippo-YAP signaling pathway in activating hPDLC autophagy by tensile stress. The expression levels of autophagy-related genes (Beclin-1, LC3, and p62) in hPDLCs were detected by real-time quantitative polymerase chain reaction. Western blot was used to detect the expression levels of autophagy-related proteins (Beclin-1, LC3-Ⅱ/LC3-Ⅰ, and p62) and Hippo-YAP pathway proteins (active-YAP and p-YAP) in hPDLCs. Immunofluorescence was used to locate autophagy-related proteins (LC3-Ⅱand p62) and Hippo-YAP pathway proteins (active-YAP) of hPDLCs. RESULTS: CTS-activated autophagy in hPDLCs and expression of autophagy-related proteins initially increased and then decreased; it began to increase at 30 min, peaked at 3 h, and decreased (P<0.05). CTS increased the expression of active-YAP protein and decreased the expression of p-YAP protein (P<0.05). When XMU-MP-1 inhibited the Hippo-YAP signaling pathway (P<0.05), active-YAP protein was promoted to enter the nucleus and autophagy expression was enhanced (P<0.05). CONCLUSIONS: The Hippo-YAP signaling pathway is involved in the regulation of autophagy activation in hPDLCs under CTS.


Asunto(s)
Vía de Señalización Hippo , Ligamento Periodontal , Humanos , Ligamento Periodontal/metabolismo , Beclina-1/metabolismo , Células Cultivadas , Autofagia
5.
Altern Ther Health Med ; 29(6): 300-305, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37318895

RESUMEN

Context: Hydrocephalus refers to excessive secretion of cerebrospinal fluid, its insufficient absorption, or its blocked circulation and frequently occurs after a cerebral hemorrhage. The mortality and disability rates for cerebral hemorrhage are high. Objective: The study intended to evaluate the clinical efficacy of integrated traditional Chinese and Western medicine in the treatment of hydrocephalus after a cerebral hemorrhage, using systematic screening and analysis of published literature. Design: The research team performed a meta-analysis by searching databases-PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang database, and Chinese Biomedical Literature-and collected Chinese and English publications from the establishment of each database until December 2022 discussing studies that used a TCM treatment that promoted blood circulation and removed blood stasis, combined with conventional western medicine, for hydrocephalus after cerebral hemorrhage. The keywords were promoting blood circulation and removing blood stasis, cerebral hemorrhage, and hydrocephalus. The team performed the meta-analysis using RevMan 5.3. Results: The research team found five relevant studies, all of which were randomized controlled trials. The clinical efficacy TCM combined with conventional Western medicine was significantly better than that of other treatments [MD = 1.77, 95% CI (0.23, 3.31), Z = 12.18, P < .001]. The NIHSS score after the integrated treatments also improved significantly more than those of other treatments [MD = -2.54, 95% CI (-4.07, -1.01), Z = 5.16, P < .00001]. Conclusions: Activating blood circulation and removing blood stasis using TCM, combined with conventional Western medicine, can achieve ideal therapeutic effects for patients with hydrocephalus after a cerebral hemorrhage, which can have a positive influence on clinical efficacy and reduce the NIHSS score, and the combined treatments have a clinical value.


Asunto(s)
Medicamentos Herbarios Chinos , Hidrocefalia , Humanos , Medicamentos Herbarios Chinos/uso terapéutico , Medicina Tradicional China/métodos , Resultado del Tratamiento , Hidrocefalia/etiología , Hidrocefalia/inducido químicamente , Hemorragia Cerebral/inducido químicamente , Hemorragia Cerebral/tratamiento farmacológico
6.
Int J Biol Macromol ; 207: 484-492, 2022 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-35278513

RESUMEN

Conductive hydrogel flexible sensors have attracted considerable research interest because of their good conductivity, flexibility, and biocompatibility. However, conventional hydrogels suffer from dehydration under ambient environments and freezing at low temperatures. Herein, we prepared a chitin/polyacrylamide organohydrogel with highly stretchable, anti-freezing, and anti-drying properties. This organohydrogel was creatively prepared by one-step radical polymerization in the chitin and calcium chloride/methanol (Ca solvent) aqueous solution. Benefiting from the chitin/Ca solvent system, the organohydrogel shows relatively high stretchability (improve ~5 times), excellent anti-freezing (up to -80 °C) upon long-term storage, and anti-drying (67 days under normal environment) performance. What's more, the reversible noncovalent bonds in the organohydrogel endow it with repeatable multi-purpose adhesion and rapid self-healing, while the abundant free ions grant it good conductivity to be a flexible sensor. Therefore, it is promising that this chitin-based conductive organohydrogel with multifunctionality would provide wide application scopes of flexible electronic devices.


Asunto(s)
Quitina , Hidrogeles , Conductividad Eléctrica , Hidrogeles/química , Iones/química , Solventes
7.
J Colloid Interface Sci ; 608(Pt 2): 1414-1421, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34742061

RESUMEN

The use of functional biodegradable wastes to treat environmental problems would create minimal extra burden to our environment. In this paper, we propose a sustainable and practical strategy to turn spent coffee ground (SCG) into a multifunctional palladium-loaded catalyst for water treatment instead of going into landfill as solid waste. Bleached delignified coffee ground (D-SCG) has a porous structure and a good capability to reduce Pd (II) to Pd (0). A large amount of nanocellulose is formed on the surface of SCG after bleaching by H2O2, which anchors and disperses the palladium nanoparticles (Pd NPs). The D-SCG loaded with Pd NPs (Pd-D-SCG) is superhydrophilic, which facilitates water transport and thus promotes efficient removal of organic pollutants dissolved in water. Pd-D-SCG exhibits excellent room temperature catalytic activity for the removal of 4-nitrophenol (4-NP) and methylene blue (MB) in water and shows good chemical stability and recyclability in water, with no obvious decrease even after five repeated cycles.


Asunto(s)
Nanopartículas del Metal , Paladio , Café , Peróxido de Hidrógeno , Porosidad
8.
Materials (Basel) ; 12(19)2019 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-31547568

RESUMEN

The development of ecofriendly procedures to avoid the use of toxic chemicals for the synthesis of stable silver nanoparticles (AgNPs) is highly desired. In the present study, we reported an eco-friendly and green technique for in situ fabrication of AgNPs on bleached hardwood pulp fibers (bhpFibers) using D-glucuronic acid as the only reducing agent. Different amounts of D-glucuronic acid were introduced and its effect on the size and distribution of AgNPs on the bhpFibers was discussed. The morphology and structures of bhpFibers@AgNPs were proved by electron microscope-dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS). Then, a series of bhpFibers@AgNPs with different AgNPs loadings were also prepared by adjusting the concentration of the AgNO3 solution. After a papermaking process via vacuum filtration, the prepared papers displayed an outstanding antibacterial performance against Escherichia coli (gram -negative) and Staphylococcus aureus (gram-positive). It is foreseeable that the bhpFibers@AgNPs have a promising application in the field of biomedical.

9.
J Agric Food Chem ; 67(31): 8700-8705, 2019 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-31294561

RESUMEN

This study reported a new headspace gas chromatography (HS-GC) for simultaneously determining the degree of deacetylation (DD) and the degree of substitution (DS) in carboxymethyl chitosan (CMCS), which were based on HS-GC measuring the amounts of CO2 released from both the bicarbonate decomposition suppressed by -NH2 and the reaction between the bicarbonate and the acidified carboxymethyl and amino groups in CMCS. The results showed that the present method has a good measurement precision (RSD < 2.55%) and accuracy (relative differences <5.90%). Compared with the current titration-based method, the present HS-GC techniques provide a more reliable testing in the quantification of amino and carboxymethyl contents in CMCS. Moreover, since the HS-GC can perform an automated sample reaction equilibration and measurement, it could be much more efficient than the existing methods in the batch sample analysis.


Asunto(s)
Quitosano/análogos & derivados , Cromatografía de Gases/métodos , Acetilación , Quitosano/química
10.
J Nanosci Nanotechnol ; 19(11): 7261-7268, 2019 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-31039884

RESUMEN

A full-cellulose derived hydrogel, composed of carboxymethyl cellulose (CMC) and nanofibrillated cellulose (NFC), was successfully manufactured and immobilized with Pd/Fe bimetallic nanoparticles for the dechlorination of 2,4,6-trichlorophenol. The NFC-reinforced CMC hydrogels with or without loading of bimetallic nanoparticles were characterized by Fourier transform infrared spectroscopy, Transmission electron microscopy, Scanning electron microscopy-energy dispersive X-ray, and X-ray diffraction analyses. The effect of amounts of NFC on the loading capacity of Pd/Fe, mechanical properties and specific Brunauer-Emmett-Teller surface areas of NFC-reinforced CMC hydrogel was also investigated. The experimental results showed that Pd/Fe bimetallic nanoparticles were dispersed and fixed in the hydrogel matrix with the nanosize spherical shape. The hydrogel would protect the Pd/Fe nanoparticles from oxidation, and thus providing long-term stability in comparison with only NFC-coated Pd/Fe nanoparticles. The hydrogel loaded with Pd/Fe nanoparticles, as a soft material catalytic system, was investigated to dechlorinate 2,4,6-trichlorophenol and was found to be very effective.

11.
Front Pharmacol ; 10: 141, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30863310

RESUMEN

Nanomaterials with localized surface plasmon resonance (LSPR) have exquisite optical properties, which allow a wide range of applications. Non-stoichiometric copper sulfides with active LSPR have drawn great attention, because its LSPR peak falls in the NIR region that is suitable for deep bioimaging and photothermal therapy (PTT). Despite numerous biomedical applications, the biocompatibility and toxicity of copper sulfides have not been studied systematically. In this contribution, we synthesized the ultrasmall biocompatible copper sulfide nanoparticle encapsulated within bovine serum albumin (BSA), CuS@BSA. The physical features of CuS@BSA were characterized. The MTT and flow cytometry assays were performed. The in vitro PTT was also investigated. The results indicated that such CuS@BSA nanoparticle had an average TEM size of 8 nm, and an average DLS size of 15 nm. A lower concentration of CuS@BSA was not toxic to HeLa cells, but the critical apoptotic events occurred in HeLa cells after co-incubation with 45 µg/mL CuS@BSA for 48 h. The photothermal effect of the CuS@BSA in aqueous medium were concentration-dependent and time-dependent, which were also verified by flow cytometry and microscopy, while the CuS@BSA were co-cultured with HeLa cells and treated with laser. This work designed an ultrasmall potential biocompatible nanoparticle, CuS@BSA, for cancer photothermal therapy, and provided the toxic information to safely guide its biomedical applications.

12.
Anal Bioanal Chem ; 410(13): 3111-3117, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29552734

RESUMEN

This work reports on a simple method for the determination of lysine content by an in situ sample pretreatment and headspace gas chromatographic measurement (HS-GC) technique, based on carbon dioxide (CO2) formation from the pretreatment reaction (between lysine and ninhydrin solution) in a closed vial. It was observed that complete lysine conversion to CO2 could be achieved within 60 min at 60 °C in a phosphate buffer medium (pH = 4.0), with a minimum molar ratio of ninhydrin/lysine of 16. The results showed that the method had a good precision (RSD < 5.23%) and accuracy (within 6.80%), compared to the results measured by a reference method (ninhydrin spectroscopic method). Due to the feature of in situ sample pretreatment and headspace measurement, the present method becomes very simple and particularly suitable to be used for batch sample analysis in lysine-related research and applications. Graphical abstract The flow path of the reaction and HS-GC measurement for the lysine analysis.


Asunto(s)
Cromatografía de Gases/instrumentación , Lisina/análisis , Dióxido de Carbono/análisis , Celulosa/química , Cromatografía de Gases/métodos , Diseño de Equipo , Límite de Detección , Ninhidrina/química , Bases de Schiff/química
13.
J Sep Sci ; 41(7): 1576-1581, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29316240

RESUMEN

We report on a headspace gas chromatographic method for determining the content of 3-chloro-1,2-propanediol in polyamideamine epichlorohydrin resin solution. It was based on quantitatively converting 3-chloro-1,2-propanediol to formaldehyde by periodate oxidation in a closed headspace sample vial at a room temperature for 10 min, and then to methanol by borohydride reduction at 90°C for 40 min followed by the headspace gas chromatographic measurement. The results showed that the present method has an excellent measurement precision (relative standard deviation < 2.60%) and accuracy (recoveries from 96.4-102%) in 3-chloro-1,2-propanediol analysis. The limit of quantitation was 0.031 mg/mL. It is simple and suitable for determining the 3-chloro-1,2-propanediol content in polyamideamine epichlorohydrin resin solution.

14.
Chemosphere ; 194: 297-305, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29216549

RESUMEN

In this study, we reported on the nano-scale nickel/iron particles loaded in carboxymethyl/nanofibrillated cellulose (CMC/NFC) hydrogel for the dechlorination of o-dichlorobenzene (DCB) in aqueous solution. The biodegradable hydrogel may provide an ideal supporting material for fastening the bimetallic nano-scale particles, which was examined and characterized by TEM, SEM-EDX, FT-IR and BET. The performance of the selected bimetallic particles was evaluated by conducting the dechlorination of DCB in the solution under different reaction conditions (e.g., pH, dosage of nickel/iron nanoparticles and temperature). The results showed that about 70% of DCB could be dechlorinated at 20 °C in 8 h, which indicated that the immobilized reactive material had a high reduction activity when Ni/Fe loading dosage in the hydrogel (18 wt%) was considered. Moreover, the reduction behavior agreed to the pseudo-first order reaction, in which the dechlorination rate was irrelative to the pH aqueous solution. A kinetic model for predicting the concentration of DCB during the reduction reaction was established based on the experimental data.


Asunto(s)
Clorobencenos/química , Halogenación , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Cinética , Celulosa/química , Hierro/química , Modelos Teóricos , Nanopartículas/química , Níquel/química , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura
15.
J Chromatogr A ; 1530: 19-22, 2017 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-29132821

RESUMEN

This paper reports on an ionic-liquid assisted headspace gas chromatographic (HS-GC) for the determination of the content of alkyl ketene dimer (AKD) in its latex samples, in which the GC system was equipped with a thermal conductivity detector (TCD). The method was based on the AKD hydrolysis conducted in 1-butyl-3-methylimidazolium chloride (ionic-liquid) added medium at 100°C for 10min in a closed headspace sample vial, and the measured CO2 (the resulting product of the hydrolysis) by HS-GC. The results showed that the present method has a good measurement precision (RSD <2.3%) and accuracy (recoveries from 96 - 105%), and the limit of quantitation (LOQ) is 0.9%. The present method is very suitable to be used for the routine check of AKD content in its latex sample in mill applications. The study also showed that the content of AKD in the tested commercial latex samples were in the range of 3.5-12%.


Asunto(s)
Técnicas de Química Analítica/métodos , Cromatografía de Gases , Etilenos/análisis , Cetonas/análisis , Látex/química , Límite de Detección , Reproducibilidad de los Resultados
16.
Carbohydr Polym ; 178: 159-165, 2017 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-29050581

RESUMEN

A novel multivalent cations-triggered shape memory hydrogels were synthesized in a one-pot method, and interpenetrating double network was formed by chemically cross-linked polyacrylamide (PAM) network and physically cross-linked sodium carboxymethyl cellulose network. The temporary shape was fixed by complexation between a native biopolymer, sodium carboxymethyl cellulose (CMC), and transition metal ions, specifically Fe3+, Ag+, Al3+, Cu2+, Ni2+, and Mg2+. In particular, CMC-Fe3+ hydrogel exhibits excellent shape fixity ratio (95%). Therefore, we chose PAM/CMC1.0-Fe3+ hydrogel as the model material and further investigated its shape recovery process. It was found that a wide range of molecules and anions could be applied to break off the temporary cross-links between CMC and Fe3+. The PAM/CMC composite hydrogels also exhibited excellent tunable mechanical properties. The mechanical properties of the composite hydrogel can be adjusted by changing the cross-linking densities. The presented strategy could enrich the construction as well as application of biopolymers based shape memory hydrogels.


Asunto(s)
Resinas Acrílicas/química , Carboximetilcelulosa de Sodio/química , Cationes/química , Hidrogeles/química
17.
J Agric Food Chem ; 65(32): 7012-7016, 2017 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-28749661

RESUMEN

This study reports on a headspace-based gas chromatography (HS-GC) technique for determining the degree of substitution (DS) of cationic guar gum during the synthesis process. The method is based on the determination of 2,3-epoxypropyltrimethylammonium chloride in the process medium. After a modest pretreatment procedure, the sample was added to a headspace vial containing bicarbonate solution for measurement of evolved CO2 by HS-GC. The results showed that the method had a good precision (relative standard deviation of <3.60%) and accuracy for the 2,3-epoxypropyltrimethylammonium chloride measurement, with recoveries in the range of 96-102%, matching with the data obtained by a reference method, and were within 12% of the values obtained by the more arduous Kjeldahl method for the calculated DS of cationic guar gum. The HS-GC method requires only a small volume of sample and, thus, is suitable for determining the DS of cationic guar gum in laboratory-scale process-related applications.


Asunto(s)
Cromatografía de Gases/métodos , Galactanos/química , Mananos/química , Gomas de Plantas/química , Cationes/química , Galactanos/síntesis química , Mananos/síntesis química , Estructura Molecular , Gomas de Plantas/síntesis química
18.
Artículo en Inglés | MEDLINE | ID: mdl-28340395

RESUMEN

A quint-wavelength UV spectroscopy for rapid determination of dichlorobenzene (DCB), chlorobenzene (CB) and benzene (B) was developed for the dechlorination process of DCB reduced by nanoscale zero-valent Fe/Ni bimetal. Based on the absorbance measurements at 260, 269, 277, 290 and 300nm, the equations for calculating the concentration of DCB and CB and B were established, in which the spectral interference from the nanoparticles could be effectively minimized. The results show that the present method has a good measurement precision (the relative standard deviations are within 2.0%) and accuracy (the recoveries are between 89 and 111%) in the DCB, CB and B's quantification. The present method is simple, rapid, and such a methodology is very suitable to be used for evaluating the dechlorination performance of chlorinated aromatic compounds in the presence of bimetal nanoparticle.

19.
J Chromatogr A ; 1496: 163-166, 2017 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-28351537

RESUMEN

This study demonstrated a headspace gas chromatographic (HS-GC) method for the determination of residual epichlorohydrin (ECH) and the by-product 1,3-dichloro-2-propanol (DCP) in polyamine epichlorohydrin (PAE) solution. It was based on the vapor-liquid phase equilibrium of these analytes at 60°C for 30min in a closed headspace sample vial before GC measurement. It was found that matrix of the PAE solution had the effect on the headspace equilibrium of these species and therefore a standard addition must be applied in the method validation. The results showed that the present method has a good measurement precision (RSD <2.90%) and accuracy (recoveries from 93.6 to 105%), and the limit of quantitation (LOQ) is 3.75mg/L for ECH and 0.8g/L for DCP. The present method is suitable to be used for analyzing the chlorinated volatile organic compounds in the commercial PAE resin solutions.


Asunto(s)
Cromatografía de Gases , Epiclorhidrina/análisis , Poliaminas/química , Compuestos Orgánicos Volátiles/análisis , Límite de Detección , Soluciones/química , alfa-Clorhidrina/análogos & derivados , alfa-Clorhidrina/análisis
20.
Chem Commun (Camb) ; 47(20): 5873-5, 2011 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-21499625

RESUMEN

A well-designed type of ultrathin carbon shell coating a silver core was prepared for the first time through an alternate adsorption and carbonization method. The obtained ultrathin carbon shell shows prominent advantages, including sufficient uniformity, better chemical stability than silica or alumina, biocompatibility, being free of pin-holes and low cost.

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